The Rainbow and the Stars

What Are the Stars Made Of?


The study of rainbows, and of optics in general, changed the way we understand the universe and ourselves. Once we believed that the sky was a realm of perfection and magic. Now we understand that we are actually part of the universe, and that there is no real dividing line between Earth and space.

The patterns of coloured light generated by chemical elements — called emission spectra and absorption spectra — show that both we and the stars are made of the same stuff.

This discovery is one of the most revealing and awe-inspiring discoveries in human history.